I thought I would respond to this as it has taken me a while to find the time to try this again.
I had success and then ultimately failure.
Using the ‘acpi’ and ‘Windows 2015’ commands in Grub didn’t work.
But adding the following did…
acpi_osi=! acpi_osi='Windows 2009'
This allowed me to have Manjaro running fine on the Intel Chip. So I updated Grub and I then followed your advice to use MHWD to install the hybrid intel/nvidia drivers.
after a reboot everything was fine, the drivers performed fine and all was good, until I realised it was still a fresh install so Octopi had 576 updates waiting for me. Stupidly I just let Octopi update them all without thinking about driver updates or anything else that may be included in the 576 packages.
Low and behold as soon as the update was done, I was back to a system that wouldn’t boot. I just got a black screen after Grub appeared and after I selected ‘Manjaro’.
So I need to retrace my steps until I get to the updates and try and work out what update may have thrown everything out.
But at least I had some success (of sorts).